How to Display and adjust an RTC

Device 16F876 ' We're using a 16F876 device with DS1307 RTC
' and 2*32 LCD default connection

REMARKS on ' Enable remarks in the source
Declare XTAL 4
Declare SDA_PIN PortC.4 ' I2C
Declare SCL_PIN PortC.3

Adcon1 = 7

Symbol SOUT=PortB.0 ' Assign the Speaker PortB.0

dim INDX as Byte
dim LDAT as Byte
dim SEC as byte
dim MN as byte
dim HOUR as byte 'Time Var
dim DAY as byte
dim DATE as byte
dim MONTH as byte
dim YEAR as byte
dim VR as byte

dim BIN_RVAL as byte
dim BCD_RVAL as byte
dim BIN2BCD_VAL as byte
dim BCD2BIN_VAL as byte 'BCD/BIN Conver Var
dim TEMP1 as Byte
dim TEMP2 as byte

dim Key as byte
dim KeyD as byte
dim BTNVAR1 as byte 'Button Var
dim BTNVAR2 as byte
dim BTNVAR3 as byte

Data "SunMonTueWedThuFriSatJanFebMarAprMayJunJlyAugSepO ctNovDec"

Delayms 50 'powerup delay
gosub HI 'Start up Beep
'Busout $D0,$00,[$00] 'Start the clock
'Busout $D0,$07,[$10]

'Busout $D0,$02,[$18] '2lines to set the time
'Busout $D0,$01,[$27]
'Busout $D0,$03,[$05] 'Day
'Busout $D0,$04,[$29] 'Date
'Busout $D0,$05,[$04] 'Month
'Busout $D0,$06,[$04] 'Year

'Busout $D0,$07,[$11] 'LED on
'Busout $D0,$07,[$10] 'LED Flash Output from DS 1307
'Busout $D0,$07,[$00] 'LED off

Start:
Cls
gosub ZROBTNVAR
RunDisp: 'Main Prog
Gosub Disp_TIM
Key = 0
KeyD = 255
gosub Keys
If Key = 1 Then gosub ZROBTNVAR : goto MinAdj
goto RunDisp
MinAdj:
Cursor 2,2
Print "Adj Min "
Gosub TimAdj
If Key = 1 then gosub ZROBTNVAR : goto HourAdj
If Key = 2 then gosub MinP
If Key = 3 then goto Start
goto MinAdj
HourAdj:
Cursor 2,2
Print "Adj Hour"
Gosub TimAdj
If Key = 1 then gosub ZROBTNVAR : goto DayAdj
If Key = 2 then gosub HourP
If Key = 3 then goto Start
goto HourAdj
DayAdj:
Cursor 2,2
Print "Adj Day/Date"
Gosub TimAdj
If Key = 1 then gosub ZROBTNVAR : goto MonthAdj
If Key = 2 then gosub DayP
If Key = 3 then goto Start
goto DayAdj
MonthAdj:
Cursor 2,2
Print "Adj Month/Year"
Gosub TimAdj
If Key = 1 then gosub ZROBTNVAR : goto MinAdj
If Key = 2 then gosub monthP
If Key = 3 then goto Start
goto monthAdj
TimAdj:
Gosub PrtPN
KeyD = 15
Gosub Disp_Tim
Key = 0
gosub Keys
Return
MinP:
BCD2BIN_VAL = MN
gosub BCD2BIN
BIN_RVAL = BIN_RVAL + 1
If BIN_RVAL > 59 Then BIN_RVAL = 0
BIN2BCD_VAL = BIN_RVAL
gosub BIN_TO_BCD
Busout $D0,$01 ,[BCD_RVAL] 'Save Mins
return
HourP:
BCD2BIN_VAL = Hour
gosub BCD2BIN
BIN_RVAL = BIN_RVAL + 1
If BIN_RVAL > 23 Then BIN_RVAL = 0
BIN2BCD_VAL = BIN_RVAL
gosub BIN_TO_BCD
Busout $D0,$02,[BCD_RVAL] 'Save Hours
return
DayP:
Day = Day + 1
If Day > 7 Then Gosub DateP
If Day > 7 Then Day = 1
Busout $D0,$03,[Day] 'Save Day
return
DateP:
BCD2BIN_VAL = Date
gosub BCD2BIN
BIN_RVAL = BIN_RVAL + 1
If BIN_RVAL > 31 Then BIN_RVAL = 1
BIN2BCD_VAL = BIN_RVAL
gosub BIN_TO_BCD
Busout $D0,$04,[BCD_RVAL] 'Save Date
return
MonthP:
Month = month + 1
If Month > 12 Then Gosub YearP
If month > 12 Then Month = 1
Busout $D0,$05,[month] 'Save Month
return
YearP:
BCD2BIN_VAL = Year
gosub BCD2BIN
BIN_RVAL = BIN_RVAL + 1
If BIN_RVAL > 20 Then BIN_RVAL = 0
BIN2BCD_VAL = BIN_RVAL
gosub BIN_TO_BCD
Busout $D0,$06,[BCD_RVAL] 'Save Years
return
Disp_TIM:
Busin $D1,$3F,[sec,sec,mn,hour,day,date,month,year]
Cursor 1,4 'Set Display to beginning
Vr=(day*3)-3 ' Display Day/Date
Restore Vr
For Indx=0 to 2
read Ldat
Print Ldat
Next
Cursor 1,8
BCD2BIN_VAL=date
gosub BCD2BIN
Gosub DispBin
Cursor 1,11
Vr = (((month & $f0)>>4)*10)+(month & $0f)
Vr=(Vr*3)+18
Restore Vr
For Indx=0 to 2
read Ldat
Print Ldat
Next
Print " 20"
BCD2BIN_VAL=year
gosub BCD2BIN
Gosub DispBin
Cursor 1,22
BCD2BIN_VAL=hour ' Display Hours/Mins
gosub BCD2BIN
Gosub DispBin
Print ":"
BCD2BIN_VAL=mn
gosub BCD2BIN
Gosub DispBin
Print ":"
BCD2BIN_VAL=sec
gosub BCD2BIN
Gosub DispBin
Return
BIN_TO_BCD:
TEMP1 = DIG BIN2BCD_VAL, 0
TEMP2 = DIG BIN2BCD_VAL, 1
TEMP2 = TEMP2 << 4 ' MOVE NUMBER OVER TO 2ND NIBBLE
BCD_RVAL = TEMP1 ^ TEMP2
Return
BCD2BIN:
TEMP1 = BCD2BIN_VAL & $F ' CONVERT THE VALUES FROM BCD TO BIN
TEMP2 = BCD2BIN_VAL & $F0 ' MASK OF EITHER SIDE
TEMP2 = TEMP2 >>4 ' DIVIDE BY 16
TEMP2 = TEMP2 * 10 ' X BY 10
BIN_RVAL = TEMP1 + TEMP2 ' NOW ADD THE FIRST NUMBER YOU THOUGHT OF
Return
DispBin:
Print Dec2 BIN_RVAL
Return
PrtPN:
Cursor 2,25
Print "Adj +"
Return
ZROBTNVAR:
Gosub Click
BTNVAR1 = 0 : BTNVAR2 = 0 : BTNVAR3 = 0
Return
Keys:
Gosub ConDly
Button PortA.3,1,KeyD,1,BTNVAR1,1,Key1
Button PortA.4,1,KeyD,1,BTNVAR2,1,Key2
Button PortA.5,1,KeyD,1,BTNVAR3,1,Key3
Return
Key1:
Key = 1
Return
Key2:
Key = 2
Return
Key3:
Key = 3
Return
ConDly:
Delayms 30
Return
Click:
Sound SOUT,[120,10]
return
HI:
Sound SOUT,[70,25]
Sound SOUT,[100,15]
Return

End